Energy drinks can be harmful to kids and adolescents, and should not be sold or marketed to children under 18, according to a new study by a consumer advocacy group.

"Something needs to be done to reduce the dangers of these products to children," says Jennifer Harris, a co-author of the study and director of marketing initiatives at the Rudd Center for Food Policy and Obesity at the University of Connecticut, in a phone interview. "Companies say these products are safe to market and sell to children as young as 12, but the evidence says otherwise."

Like tobacco, says Harris, energy drinks such as Red Bull and Monster should be kept behind the counter with sales limited to adults. "A lot of parents just don't understand how dangerous these are for kids" she says.

Kids who drink high-caffeinated energy drinks can suffer negative health, social, emotional and behavioral problems, the study says. The number of hospital emergency-room visits by 12- to 17-year-olds linked to energy drinks increased from 1,145 in 2007 to 1,499 in 2011, says the study, which was funded by the Robert Wood Johnson Foundation. It appears in the April issue of the journal Nutrition Reviews.

Energy drink sales continue to explode in the U.S. and globally. The global energy drink industry leaped to about $27.5 billion last year from about $3.8 billion in 1999, reports Euromonitor, a market research specialist. Within the beverage industry, where soft drink sales continue to decline, much of the growth comes from energy drinks.

Sales of energy drinks jumped 53% between 2007 and 2012, according to the study, which claims to be the first to fully examine existing research, particularly on the marketing of energy drinks to youth under 18. Energy drink brands spent $282 million in advertising in all media in 2012, about 2.5 times the amount spent in 2008, the study notes.

The results, however, were ridiculed by the American Beverage Association, an industry trade group.

"Energy drinks have been enjoyed safely by millions of people around the world for more than 25 years, and in the U.S. for more than 15 years," says the trade group, in a statement. "This report ignores crucial data about energy drinks and caffeine consumption in the U.S. Based on the most recent government data reported in the journal Pediatrics, children under 12 have virtually no caffeine consumption from energy drinks."

The group also says that leading energy drink manufacturers voluntarily go far beyond all federal requirements when it comes to labeling and education. "In fact, ABA member companies voluntarily display total caffeine content — from all sources — on their packages along with advisory statements indicating that the product is not recommended for children, pregnant or nursing women and persons sensitive to caffeine. They also have voluntarily pledged not to market these products to children or sell them in K-12 schools," says the statement.

Energy drinks, ingredients and labeling, are regulated by the FDA and, like most consumer products, their advertising is subject to oversight from the U.S. Federal Trade Commission.

But Harris points out that the American Academy of Pediatrics recommends that children and adolescents not consume energy drinks. Also, the American Medical Association supports banning the marketing of energy drinks to kids under 18, she notes.

If the industry doesn't take more concrete steps to protect children under 18, Harris says, "government policies may be necessary."